1. Field of Invention
This invention relates generally to an apparatus and method for loading and reloading electronically transmitted documents. More particularly, this invention relates to an apparatus and method for loading web pages, such as HTML pages, where some portions are marked as non-cacheable and other portions are marked as cacheable.
2. Description of Related Art
The linking of desktop computers to other computers may be done using various networking techniques. For example, a local area network (LAN) typically uses a central computer known as a server, and multiple desktop computers connected to the server. In a LAN, the server contains information and programs which each desktop computer connected to the server can access and utilize.
Another way of sharing information among computers involves a network of computers known as the Internet and the World Wide Web (WWW). In the WWW, individual computers access information located on other computers. The information is accessed via an access image or page. Each page of information on the WWW has an address, known as a uniform resource locator (URL). Only the unique URL is needed in order to access the desired information on another computer through the Internet.
Restricting access to a limited number of computers in an Internet-type environment results in another form of networking known as an Intranet. Intranets represent a way for multiple computers to share information among only those computers. By preventing computers outside the intranet from accessing the information contained on the server, security is improved.
Each page accessible via an intranet or the Internet is generated using an editing language. One document editing language is the hypertext mark-up language (HTML). HTML allows for the embedding of images, sounds, video streams, form fields and simple text formatting into a page. References to other pages or locations may also be embedded in the page using the URLs of the desired page or location.
Additionally, special programming languages, such as Java.RTM., have been developed to allow for rapid transfer of information among computers on both intranets and the Internet. Java.RTM. is an object-oriented programming language which can run on any computer platform (i.e., operating system), allowing different computers having different computer platforms to communicate. For example, these different platforms include Macintosh.RTM., Windows 95.RTM., Windows NT.RTM. and UNIX.
When a user desires to communicate on the Internet or on an intranet, a browser is generally required. A browser is a computer program which enables a user to look at information on other computers and retrieve information from other computers in an environment that allows for cross-platform communications. Examples of browsers include Netscape Navigator.RTM., MS Internet Explorer.RTM. and Hot Java.RTM.. Many browsers are written in Java to allow for easy cross-platform transfer of information. When the browser accesses a URL, a page of information in HTML is copied and transferred across the network into the user's computer. The information contained in the page is generally stored in a cache in local memory. The user can scroll, or otherwise navigate, within the retrieved page. When the user is finished with that particular page, another URL may be selected and accessed and another page retrieved. Should the user desire to go back to a previously accessed page, that page, if still maintained in the cache, is simply brought back to the user's view. If the user desires to determine if the current page available over the network contains updated information compared to the previously retrieved page stored in the cache, the URL may be re-accessed and the entire page retransmitted, redisplayed and re-cached, i.e., reloaded.